Blastomycosis is a disease caused by infection with the fungus Blastomyces dermatitidis. Humans and other animals (particularly dogs) are infected by inhaling aerosolized fungal spores from soil where the organism dwells. At body temperature, these spores convert to yeast forms. Acute primary pulmonary infection caused by the yeast can produce an influenza or pneumonia syndrome Although acute blastomycotic pneumonia may resolve spontaneously, progressive forms of disease can cause serious damage to the lungs, skin, bones, joints, or prostate gland.
Although serologic and skin tests play an important role in the identification and epidemiologic study of other mycoses, reliable markers of recent and remote B. dermatitidis infection are not generally available for non-invasive diagnosis and study of the epidemiologic features of blastomycosis. The best available tests involve two antigens taken from B. dermatitidis yeast, "A" antigen (see J. Green et al., 4 Curr. Microbiol. 293-96 (1980)) and "Blastomyces alkali- and water-soluble antigen (B-ASWS)" (see R. Cox et al., 10 Infect Immun. 42-47 (1974)). These two prior art antigens are impure (see K. Young et al., 33 Infect Immun. 171-177 (1981); M. Lancaster et al., 13 Infect Immun 758-762 (1976)), they appear to be a mixture of cell wall components, and tests employing them are not widely available A further problem with serologic tests using, for example, the "A" antigen has been diminished specificity as sensitivity is increased. This problem appears to result from antigen impurity and the extensive sharing of cell wall components between dimorphic fungi, particularly B. dermatitidis and Histoplasma capsulatum.
It is also desirable to develop a vaccine for the disease. In this regard, approximately fifteen percent of infected humans and over two-thirds of infected dogs die when infected with this fungus.
Thus, it can be seen that a need exists for the development of a test for the presence of B. dermatitidis in an animal which has high sensitivity, high specificity, and which can easily and quickly be performed at low cost. Vaccines against the disease are also needed.